In recent years, the organic electroluminescent element (organic EL element) is being increasingly applied in the field of a flat panel display and the like. The organic EL element is attractive since a beautiful image is easily obtained thereby with low power consumption, but has the problem of sensitiveness to humidity. Therefore, it is an important task to solve the problem. When an electrode of the organic EL element is in contact with to oxygen gas or water vapor, a portion of light-emitting failure that is called a dark spot occurs due to oxidation, corrosion, or the like of the electrode.
In order to protect the organic EL element from moisture, it is known to set a layer that suppresses permeation of gas such as water vapor (gas-barrier layer). As the gas-barrier layer, for example, a thin film of silicon nitride, aluminum oxide, carbon nitride, diamond-like carbon, or the like is effective.
However, these gas-barrier layers are brittle against impacts from the outside or bend, and easily break, since it is necessary that the internal structure of these gas-barrier is precise from the viewpoint of suppressing permeation of gas.
For this, methods of imparting toughness against the impacts or bend by sealing the gas-barrier layer and the organic EL element with a flexible organic material, for example a sealing method of using an epoxy resin, are proposed (Patent Literatures 1 to 4).
However, the sealing method of using the epoxy resin is required to undergo a curing step using heat, ultraviolet irradiation, or the like, and the heat or the ultraviolet irradiation has the problem of damage to the organic EL element. Further, the epoxy resin-hardened material generally belongs to the group having a relatively low flexibility among the organic high molecular compounds, and as a result, further improvement of bending property is required.